Certified Java Programmer Mock Exam

Question 1

interface A {
  void m1();            // 1
  public void m2();     // 2
  protected void m3();  // 3
  private void m4();    // 4
}

Compile-time errors are generated at which lines?

Question 2

Which of the following are modifiers that can be applied to a method declaration within an interface?

Question 3

Which of the following is a modifier that can be applied to a method declaration within an interface?

Question 4

interface A {void m1();}                      // 1
class B implements A {public void m1() {}}    // 2
class C implements A {protected void m1() {}} // 3
class D implements A {private void m1() {}}   // 4
class E implements A {void m1() {}}           // 5 

Compile-time errors are generated at which lines?

Question 5

Which of the following are true statements?

Question 6

interface A {
  void m1();              // 1
  public void m2();       // 2
  protected void m3();    // 3
  private void m4();      // 4
  abstract void m5();     // 5
}

Compile-time errors are generated at which lines?

Question 7

interface A {
  final void m1();        // 1
  synchronized void m2(); // 2
  native void m3();       // 3
  abstract void m4();     // 4 
  public void m5();       // 5
}

Compile-time errors are generated at which lines?

Question 8

interface A {void main(String[] args);}               // 1
interface B {public void main(String[] args);}        // 2
interface C {public static void main(String[] args);} // 3
interface D {protected void main(String[] args);}     // 4
interface E {private void main(String[] args);}       // 5 

Which interface declarations generate a Compile-time error?

Question 9

interface F {abstract void main(String[] args);}      // 1
interface G {synchronized void main(String[] args);}  // 2
interface H {final void main(String[] args);}         // 3
interface I {native void main(String[] args);}        // 4 

Which interface declaration does not generate a compile-time error?

Question 10

interface A {String s1 = "A"; String m1();}
interface B implements A {String s1 = "B"; String m1();}
class C implements B {
  public String m1() {return s1;}
  public static void main(String[] args) {
    A a = new C();
    System.out.print(a.m1());
}}

What is the result of attempting to compile and run the program?

Question 11

interface A {int i = 1; int m1();}
interface B extends A {int i = 10; int m1();}
class C implements B {
  public int m1() {return ++i;}
  public static void main(String[] args) {
    System.out.print(new C().m1());
}}

What is the result of attempting to compile and run the program?

Question 12

interface Z {void m1();}  // 1
class A implements Z {void m1() {}} // 2
class B implements Z {public void m1() {}} // 3
abstract class C implements Z {public abstract void m1();} // 4

A Compile-time error is generated at which line?

Question 13

interface Z {void m1();}  // 1
class D implements Z {public final void m1() {}}    // 2
class E implements Z {public synchronized void m1() {}} // 3
class G implements Z {public native void m1();}     // 4

A Compile-time error is generated at which line?

Question 14

class Leg{}
class Fur{}
abstract class Pet {
  public abstract void eat();
  public abstract void sleep();
}
class Dog extends Pet {
  Leg leftFront = new Leg(), rightFront = new Leg();
  Leg leftRear = new Leg(), rightRear = new Leg();
  Fur fur = new Fur();
  public Fur shed() {return fur;}
  public void eat() {}
  public void sleep() {}
}
class Cat extends Dog {
  public void ignoreOwner() {}
  public void climbTree() {}
}

Which of the following statements is not a true statement?

Question 15

class A {
  A() {System.out.print("CA ");}
  static {System.out.print("SA ");}
}
class B extends A {
  B() {System.out.print("CB ");}
  static {System.out.print("SB ");}
  public static void main (String[] args) {
    B b = new B();
}}

What is the result of attempting to compile and run the above program?

Question 16

interface I10 {
  String name = "I10"; String s10 = "I10.s10";
}
interface I20 {
  String name = "I20"; String s20 = "I20.s20";
}
class C10 implements I10, I20 {            // 1
  public static void main(String[] args) {
    System.out.print(s10+",");             // 2
    System.out.print(s20+",");             // 3
    System.out.print(name);                // 4
}}

What is the result of attempting to compile and run the program?

Question 17

interface I10 {
  String name = "I10"; String s10 = "I10.s10";
}
interface I20 {
  String name = "I20"; String s20 = "I20.s20";
}
class C20 implements I10, I20 {         // 1
  public static void main(String[] args) {
    System.out.print(I10.s10+",");      // 2
    System.out.print(I20.s20+",");      // 3
    System.out.print(I20.name);         // 4
}}

What is the result of attempting to compile and run the program?

Question 18

class A {String s1="A";}
class B extends A {String s1="B";}
class C extends B {String s1="C";}
class D extends C {
  String s1="D";
  void m1() {
    System.out.print(this.s1  + ",");      // 1
    System.out.print(((C)this).s1  + ","); // 2
    System.out.print(((B)this).s1  + ","); // 3
    System.out.print(((A)this).s1);        // 4
  }
  public static void main (String[] args) {
    new D().m1(); // 5
}}

What is the result of attempting to compile and run the program?

Question 19

class SuperA {String s1="SuperA";}
class SuperB {String s1="SuperB";}
class A extends SuperA {
  String s1="A";
  class B extends SuperB {  // 1
    String s1="B";
    void m1() {
      System.out.print(this.s1 + ",");   // 2
      System.out.print(super.s1 + ",");  // 3
      System.out.print(A.this.s1 + ","); // 4
      System.out.print(A.super.s1);      // 5
    }
  }
  public static void main (String[] args) {
    new A().new B().m1();  // 6
}}

What is the result of attempting to compile and run the program?

Question 20

class A {void m1() {System.out.print("A");}}
class B extends A {void m1(){System.out.print("B");}}
class C extends B {void m1() {System.out.print("C");}}
class D extends C {
  void m1() {System.out.print("D");}
  void m2() {
    m1();
    ((C)this).m1(); // 1
    ((B)this).m1(); // 2
    ((A)this).m1(); // 3
  }
  public static void main (String[] args) {
    new D().m2(); // 4
}}

What is the result of attempting to compile and run the program?

Question 21

class A {public void m1() {System.out.print("A1");}}
class B extends A {
  public void m1() {System.out.print("B1");}
  public void m2() {System.out.print("B2");}
}
class C {
  public static void main(String[] args) {
    A a1 = new B();
    a1.m1();      // 1
    a1.m2();      // 2
   ((B)a1).m1();  // 3
   ((B)a1).m2();  // 4
}}

What is the result of attempting to compile and run the program?